The focusing optics x-ray solar imager: FOXSI

Säm Krucker, Steven Christe, Lindsay Glesener, Shin Nosuke Ishikawa, Stephen McBride, David Glaser, Paul Turin, R. P. Lin, Mikhail Gubarev, Brian Ramsey, Shinya Saito, Yasuyuki Tanaka, Tadayuki Takahashi, Shin Watanabe, Takaaki Tanaka, Hiroyasu Tajima, Satoshi Masuda

Research output: Chapter in Book/Report/Conference proceedingConference contribution

16 Scopus citations


The Focusing Optics x-ray Solar Imager (FOXSI) is a sounding rocket payload funded under the NASA Low Cost Access to Space program to test hard x-ray (HXR) focusing optics and position-sensitive solid state detectors for solar observations. Today's leading solar HXR instrument, the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) provides excellent spatial (2 arcseconds) and spectral (1 keV) resolution. Yet, due to its use of an indirect imaging system, the derived images have a low dynamic range (typically <10) and sensitivity. These limitations make it difficult to study faint x-ray sources in the solar corona which are crucial for understanding the particle acceleration processes which occur there. Grazing-incidence x-ray focusing optics combined with position-sensitive solid state detectors can overcome both of these limitations enabling the next breakthrough in understanding impulsive energy release on the Sun. The FOXSI project is led by the Space Sciences Laboratory at the University of California, Berkeley. The NASA Marshall Space Flight Center is responsible for the grazingincidence optics, while the Astro-H team at JAXA/ISAS has provided double-sided silicon strip detectors. FOXSI is a pathfinder for the next generation of solar hard x-ray spectroscopic imagers. Such observatories will be able to image the non-thermal electrons within the solar flare acceleration region, trace their paths through the corona, and provide essential quantitative measurements such as energy spectra, density, and energy content in accelerated electrons.

Original languageEnglish (US)
Title of host publicationOptics for EUV, X-Ray, and Gamma-Ray Astronomy V
StatePublished - 2011
EventOptics for EUV, X-Ray, and Gamma-Ray Astronomy V - San Diego, CA, United States
Duration: Aug 23 2011Aug 25 2011

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


ConferenceOptics for EUV, X-Ray, and Gamma-Ray Astronomy V
Country/TerritoryUnited States
CitySan Diego, CA


  • electroform-nickel replication
  • grazing-incidence optics
  • high-energy x-ray optics
  • silicon strip detectors
  • solar .ares
  • solar physics
  • sounding rocket payload


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